The occurrence of chitinolytic microbes and the colonisation and degradation of a native chitin substrate (squid pen) was studied in riverine, estuarine and marine aquatic environments m the Aberdeen area. Chitinolytic microbes were prevalent at all the sites (means: aerobic water 616ml-1, 2% of heterotrophs; anaerobic sediment 11560ml-1 0.8% of anaerobic heterotrophs). It was proposed that the chitinolytic numbers were directly influenced by the presence of chitinous material and indirectly influenced due to a heterotrophic response by organic/suspended matter levels. Hence chitinolytic numbers in the river and were largely influenced by allochthonous inputs while numbers in the sea were influenced by autochthonous production of organic and chitinous matter. From the results of a chitin assay of seawater it was extrapolated that 6.65x1013 metric tons of particulate chitin exist in the world's oceans. Chitin was found to degrade in all the sites studied. The annual rate ranged between 0.905% (river) to 0.074% (marine) squid pen day-1(approx 50mg seeded). The maximum rate recorded was 1.39% day at the river. At most of the sites the rate was positively correlated (P 0.05) with temperature. It was proposed that the marine annual rate would not cope with the annual chitin production and that degradation in the sea is mediated by the synergistic action of the chitinolytic microflora and fauna. The colonisation studies indicated that chitin was rapidly colonised at all the sites studied. The microbial numbers and biomass increased up to about 14 days after exposure, then levelled off and remained relatively constant for the remainder of each exposure period. It was proposed that the numbers of chitinolytic microbial colonisers remained relatively constant at each site studied throughout the year (i.e. changes in the degradation rate were due to variation in activity and not numbers), but the numbers and biomass of chitinolytic microbial colonisers was different between sites and this accounted for some of the variation in degradation rate recorded between sites. Samples with dense colonising biofilms and extensive filamentous growth were also characteristic of sites of relatively high chitin degradation.

No description available.

Tyre inner tubes made of butyl rubber have been found to have poor heat resistance when used in the environment of Iraq. Research investigations were undertaken to establish the causes of the problem: these consisted of examining the individual contributions of oxidative scission processes in both rubber hydrocarbon and the various processing oils. The principal method used to monitor the degradation processes was ageing in hot air using the reduction in strength for the rubber and change in chemical composition of the processing oils. This preliminary study established that the processing oil made in Iraq was found to be of different composition from the common European rubber processing oils and contributed considerably to the poor life of the butyl inner tubes. Analysis of the oil from Iraq identified the presence of trace amounts of copper (3 ppm) known, from the literature, to adversely affect the resistance of many rubbers to elevated temperatures and, as found in this work, to also degrade butyl rubber. Replacement of the butyl rubber by chlorobutyl rubber overcame the problem of inner tube degradation and an antioxidant system based on a combination of an acetone/diphenylamine (ADPA) plus mercaptobenzimidazole (MBI) with MgO was found effective in minimising chlorobutyl inner tube degradation. However, unexpectedly, the research also established that trace quantities of copper were useful as stabilisers in enhancing the heat ageing properties of chlorobutyl rubber and the addition of a particular copper salt (copper sulphatel in small proportions (3 ppm) as an anti-degradant was found beneficial. Another method studied to improve the resistance of halogenated butyl rubber to heat induced oxidative degradation tried to use ZnO as the curative, as recommended by the manufacturers of chlorobutyl rubber; however it was found that with this technique higher degradation was obtained in chlorobutyl than with the standard ZnO/ sulphurless curing system (i.e. ZnO/TMTDin proportions 5:1 phr). It was concluded from these studies that: 1. Reducing the oil level in butyl inner tubes from 25 phr to 15 phr enhances heat ageing properties of the rubber. Factory trials confirmed this finding. 2. Adding a copper inhibitor (ZDC) in the proportions 1-2 phr in butyl inner tubes was found successful in minimising oxidative degradation. 3. The existence of elemental copper in a chlorobutyl inner tube rubber formulation in the proportion 3 ppm improved the rubber properties at elevated temperatures.

No description available.

Class of 2009 Abstract / OBJECTIVES: The objective of this study was to investigate the effects of temperature excursions on insulin during standard shipping from mail-order pharmacies. METHODS: Twelve vials of insulin (six of regular and six of neutral protamine hagedorn (NPH)) were sampled at baseline and then the six experimental vials (three regular and three NPH) were shipped through the mail system from a Tucson, Arizona post office to a Tucson, Arizona residence. The other six vials were used as controls and left in a refrigerator at 5°C. Samples were taken daily and then measured for degradation using high performance liquid chromatography (HPLC). Also, samples from control vials were put in a lab oven at a constant temperature of 48°C and analyzed at Day 0 and Day 2. RESULTS: Temperatures spiked daily to near or over 50°C with a peak of 51.5°C. The low temperature never dropped under 21°C. The area under the curve (AUC) for each individual sample drawn was used to calculate a percentage of its original concentration with Day 1 set as 100%. On Day 6, both experimental vials and control vials had similar results and were within 10% of the original concentrations measured. In the oven, NPH samples that were heated for two days lost about 4% of its concentration while the regular insulin sample lost 14%. Particle sizing data of regular insulin heated in the oven was consistent with this HPLC data, and showed significant shifts in peak position. CONCLUSIONS: Insulin appears to maintain its stability after being shipped through the mail and remaining in a mailbox for an additional five days at high summer temperatures in Arizona. However, when exposed to constant high temperatures in a laboratory oven, heat appears to affect its stability.

Deforestation contributes approximately 20 percent of global annual carbon dioxide (CO2) emissions. Increased CO2 is thought to contribute to increased global temperatures. Proposals have been brought forward to use carbon finance to compensate developing countries for reducing emissions from deforestation and degradation (REDD). International negotiations at the UN Climate Change Convention in Copenhagen in December 2009 will determine if REDD Offsets will be included in a post-Kyoto Protocol framework. At the time of writing, Canada proposes to achieve a 20 percent reduction in greenhouse emissions below 2006 levels by 2020 through an intensity based cap-and-trade scheme. International forestry-based offsets are specifically excluded from the proposed Canadian regulatory scheme. The international demand for REDD Offsets will likely grow with acceptance under the proposed US scheme, and others. With proper regulations, international REDD Offsets could be included in the proposed Canadian regulatory system providing benefit to regulated entities and the developing world.

No description available.

No description available.

Die Hochmoore des Erzgebirges sind auf Grund ihrer jahrhunderte langen Nutzung und der ökosystemaren Wandelprozesse der vergangenen 10 - 15 Jahre unterschiedlich stark degradiert. Gleichzeitig sind sie durch den Austrag vergleichsweise hoher Austräge von DOC (Dissoloved Organic Carbon) gekennzeichnet. Um den Zusammenhang zwischen dem Zustand der Hochmoore, als Ergebnis in erster Linie der unterschiedlich nutzungsbedingten Degradation und den Stoffausträgen speziell den DOC-Austrägen zu erfassen, wurden mittels landschaftsökologischer Methoden Hochmoortestflächen verschiedener Zustände vergleichend untersucht. Die Ergebnisse lieferten erste Hinweise, dass in Flächen mit natürlicher Regeneration oder anthropogener Wiedervernässung vergleichsweise hohe DOC-Konzentrationen und – Austräge zu beobachten waren. Demgegenüber standen stärker degradierte Flächen mit zum Teil aktueller forstlicher Nutzung (geräumte Entwässerungsgräben), die durch geringere DOC-Konzentrationen und – Austräge charakterisiert waren. Da die gefundenen Zusammenhänge nicht endgültig belegt werden konnten, besteht insbesondere Forschungsbedarf hinsichtlich landschaftshaushaltlicher Untersuchungen unterschiedlich degradierter Hochmoore im Erzgebirge. / Natural peat bogs are known as a sinks especially for carbon because of theire special matter and water balance. The use of peat bogs requiers their drainage, but consequently the peat will decompose unreversible and peatlands turn to a source esspecially for carbon. The peat bogs in the “Erzgebirge Mountains” were used over several centuries. Thats why the peatlands existing nowadays have different states dependent on the duratian of their use. Beside the use peatlands were mostly negativly effected by processes of ecological change in the “Erzgebirge Maountains” in the last 10 to 15 years. As one result of ecological change the increased output of DOC (Dissolved Organic Carbon) into surface waters can be seen. The main source for DOC are peatlands. By the way it seems to exist a connection between the output of DOC and other dissolved substances and the state of the peatlands especially of their ditches. To research this hypothesis four test areas of different state were chosen. Their state and the output of DOC and other dissolved substances were investigated with methods from landscape ecology from 2001-2003. It was the first time, that peatlands in the “Erzgebirge Mountains” were investigated in such a way. The badest state had the test area where the ditches were cleaned in 2000/ 2001 (“Weiße Mulde”, Western “Erzgebirge Mountains”). This test area showed the lowest but constant DOC-concentrations and DOC-output during the investigation period. The test areas “Carlsfeld” and “Löffelsbach” (Western “Erzgebirge Mountains”) had the best state. The state of “Carlsfeld” is related to the narueal closed ditches, which cause the processes of self regeneration. Due to such processes the DOCconcentrations were distinctly higher but very variable in dependence on weather and runoff. The same was supposed to DOC-output. The same valuation got the test area “Löffelsbach”, because of rewetting by technical closed ditches in 2001. During the investigation period the highest DOC-concentrations of all test areas were measured there. Similar to “Carlsfeld” DOC-concentrations and –output were highly variable in dependence on weather and runoff. The state of the test area “Salzflüßchen” (Eastern “Erzgebirge Mountains”) is also related to processes of self regeneration but was valuated bader than “Carlsfeld”, because the effect of former drainage was stronger in this area. In 2005 the rewetting of the test area is planed by “Naturpark Erzgebirge/ Vogtland”. In the consequence the DOC-concentrations and –output will increase similar to “Löffelsbach”. The results of the investigations indicate that a connection exists between state of peatlands and output of dissolved substances esspecially DOC. The results are supported by national and international literature. It will be clear, that more research is necessary especially on the field of comparative investigations of peatlands with different states in the “Erzgebirge Mountains”.

In this study, the kinetic analysis of oxygen delignification of Turkish southern hardwood Kraft pulp was carried out. Kraft pulp was obtained from Mopak Dalaman pulp and paper mill. The kinetic rate data were collected in a 1 L high pressure batch reactor. The delignification experiments were carried out under a wide range of industrially significant conditions of temperature (90, 100 and 110 oC), alkali charge (1, 3, 5% on oven dry pulp), and oxygen partial pressure (0.5, 3.5, 6.5 bar). In order to achieve this objective, the study is separated into different stages. In the first stage of the work, the mass transfer effects were examined for different pulp consistencies. It was seen that the inter-fiber mass transfer resistances become negligible at the consistencies below 1%. Therefore, the experiments were performed at 0.5% consistency. In the following stage, the kinetics of oxygen delignification was studied and the governing rate equations were derived. Then, the kinetics of the carbohydrate degradation was analyzed in order to determine the extent of delignification without the reduction in the pulp strength. The delignification and the carbohydrate degredation rate during oxygen delignification increase with increasing in alkali concentration, oxygen partial pressure and temperature. However, the most effective parameters are the alkali concentration and temperature. The dimensionless terms for Kappa number, intrinsic viscosity and reaction time were used in order to generalize the results and to make them independent of the initial Kappa number, the intrinsic viscosity, experimental conditions and pulping conditions prior to oxygen delignification. These dimensionless parameters were fitted to nonlinear equations from which the control of the oxygen delignification towers can be done with a simple equation. The same approach was also used for the reported studies in the literature which allowed the comparison with the results of this study. In the final stage of the study, the simulation of the oxygen delignification unit preceding the CEHDED bleach plant is performed, in order to see the effect of oxygen delignification on the amount of total wastes coming out from the bleach plant. When an oxygen delignification unit is added to the existing CEHDED bleach plant, the amount of pollutants are decreased by 17.96% with output brightness of 92.95. When the overall process parameter optimization of the CEHDED bleach plant is done with oxygen delignification unit, the total amount of dissolved solids coming out from the six washers are decreased by 25.97% with output brightness of 89.5. In order to reduce the pollution load and chemical consumption in Mopak Dalaman pulp and paper mill, management has decided to install an oxygen delignification unit to the plant. Therefore, the rate equations obtained from this study can form a basis for the design and optimization of oxygen reactor in the mill.